Introduction
The thrust of manufacturing in the decades to come will be toward continuing reductions in cost, improvements in quality, and most dramatically for the change in manufacturing methods, a vastly increased flexibility of manufacture to respond immediately to market trends. Such flexibility has been the hallmark of the success of companies in the clothing business, for example, and is now being advocated for all types of business including those in the traditional hard goods sector. A Term, "Agile Manufacturing" has been coined to describe this new paradigm.
The provision of manufacturing systems however that can deliver agile performance while maintaining the lowest cost and highest quality is extremely difficult. In years past, these three goals each has been viewed as mutually exclusive with the others. For example, in order to reduce cost, the famous Ford assembly line eliminated flexibility to market change, creating one style and producing it for a long period of time, with at least reasonable quality. Recently the Japanese, for example in the car business, have begun to hone the traditional processes of car manufacture to a fine degree raising the level of quality well beyond its previous state, but still with very little flexibility. Other cars, such as certain exotic marquees made in much smaller quantities, achieve quality and flexibility, but at high cost. Even with these however, flexibility is still not achieved until such extremely small volumes are reached that the car becomes virtually hand made.
This being the case then, how can mass market items produced rapidly to market change in ever smaller economic lots at lowest cost to be affordable and still maintain the highest quality? It seems virtually impossible, and yet this is the goal that has been set out by, both the Japanese and American studies for achievement in the 21st century.
If this isn't enough, further thrusts toward improved performance, both environmentally and performance are required--in the car business for example being acceleration, fuel economy, etc. In order to achieve approved performance, much higher accuracies are being required in the production of key critical components.
The accuracy requirements are not simply limited to the powertrain or functional components, but also related as well to almost all other parts, such as anti-skid brake systems, and even the sheet metal body, where a relentless quality push has taken place in North America, which however at some point approaches the law of diminishing returns is taking place (since the benefits are increasingly subjective as opposed to functional).
Before proceeding to the technical aspects of the invention, there are other trends in the manufacturing technology world today. Some of these have been pinpointed in the Lehigh Study, and other recent attempts to formulate industrial policy in the United States. The area that this application and my previous work is most concerned with, is intelligent sensors, machine intelligence, and knowledge based systems. These form the building blocks on which the flexible machines and automation that can achieve the goals above in an accurate low cost manner can be built. They are also in an area that are very difficult to do, and to some degree only now begins to become possible economically due to the drastically lowering cost of the computation facilities, and the maturing of key sensor technologies, particularly electro-optics/machine vision, which would allow them to be used reliably in plant applications.
There are other trends, such as the move toward openness in the controls areas, which allows the sensory data to be imputed in a manner suitable for action on the plant floor, but without being locked up by proprietary systems. There is also obviously an ever present trend toward lower computer costs, which can be extrapolated on to produce, along with lower memory costs, a massive increase in the ability to use "knowledge and intelligence" to deal with the ever present problems on the plant floor. While the computation and memory costs are changing rapidly, sensing technologies, however, are not. It can be assumed that those in place today will, in "ever better" but not drastically changed form, provide the basis for the manufacturing systems of the year 2000 onward.
The trend toward knowledge and intelligence is manifested in the ever increasing role of software, and the operation of reliable software in these machines is critical. Also critical is that the sensory data provided, which yields the basis on which intelligence can be done is correct.
This leads to the next issue, the selection of sensors. Here, it is my thesis, that just as in the factory of today, the principal sensor is the worker's eye, so it is here that some sort of electro-optically based sensor, whether it approximates human vision or not is indeed key. There are many reasons for this, among them non-contact operation, freedom from wear, large stand-off, accuracy, multi-varied task ability, etc. I have found in the course of working in this field for the last 20 years, that most all variables that need to be sensed in the manufacture of hard goods, can be indeed sensed electro-optically, and generally best with image based sensors of some kind. In some cases, they may be better sensed by other means, such as contact gages or the like, but in general the electro-optical solution is the one with the most application, and most approximating the human.
The key though is to do what the human can do flexibly, but to also achieve the precision and the freedom from fatigue that machines can provide. The key sensor for this purpose, that can guide machines in a human like manner, but with the accuracy of the machine, is electro-optical--and generally image based--just like the human eye.